RGB (red, green, blue) LED backlights are commonly used to increase the gamut range of LED-backlit LCD televisions. Such RGB LEDs can also be used to directly display images in LED televisions (LED TVs). Each R, B, or G light or diode, however, requires a different turn-on voltage (e.g., the forward-bias voltage). As a result, when a same driving voltage is used to bias all R, G, and B LEDs in the same circuit, the R LEDs appear to consume much more power than the G and B LEDs. Various approaches use different techniques to reduce power consumption, but increase the size and cost for printed-circuit boards (PCBS) having the LEDs, due to additional components/circuitry. For example, one approach that uses three power converters, one for each R, G, and B LED also uses three inductors and numerous external components. Another approach uses a parallel driving structure, but with a complex transformer and two inductors. Another approach uses a single converter, but also uses a pulse-width modulator (PWM) current controller that consumes high power.
Like reference symbols in the various drawings indicate like elements.